电解海水对环氧涂层防腐蚀性能的影响研究

Research on Effects of Electrolytic Sea Water on Anticorrosive Performance of Epoxy Coatings

通过在天然海水及3种不同余氯浓度的电解海水中进行静态浸泡试验,研究了环氧涂层吸水率、附着力、划痕剥离、耐阴极剥离等防腐蚀性能。结果表明,在所试验的3种浓度电解海水中,环氧涂层均未起泡或剥落,试验后的涂层附着力>3.5 MPa,涂层仍保持良好的防腐性能。当电解海水中余氯浓度不超过10 mg/L时,电解海水对涂层划痕剥离及耐阴极剥离性能影响不显著,涂层失效主要是由于海水介质沿着金属-涂层界面渗透导致涂层从基材脱附;当余氯浓度达到15 mg/L时,涂层划痕剥离及耐阴极剥离性能随着试验时间的延长显著下降,高浓度余氯会加速涂层失效。

The water absorption, adhesion capability, flaking, the resistance to cathodic disbondment and other anticorrosive properties of epoxy coating were studied by static immersion in natural seawater and three electrolytic seawaters separately. The results suggested that the epoxy coating in all tested seawaters showed good anticorrosive performance, no blistering or flaking off, and the adhesion remaining higher than 3.5 MPa. When the concentration of residual was less than 10 mg/L, the electrolytic seawater had no significant influence on flaking and cathodic disbondment of the epoxy coating, and the penetration of sea water alongside the metal-coating interface led to coating detachment from the substrate. When the residual chlorine concentration reached 15 mg/L, the coating deteriorated rapidly from the aspect of flaking and cathodic protection. High concentration of chlorine could accelerate the failure of the coating.